2 caption = list of commands
4 purpose = list commands or keybindings, or print command-specific help
5 non-opts-name = [command]
8 This command acts differently depending on whether it is executed in
9 command mode or in insert mode.
11 In command mode, the help command prints the list of defined
12 keybindings. In insert mode, if no argument is given, it prints the
13 list of available commands. When called with the name of a command
14 as first argument, it prints the description of this command.